Project description:Despite known differences in immunologic features between anti-citrullinated peptide antibody (ACPA)-positive (ACPA+) and ACPA-negative (ACPA-) early rheumatoid arthritis (eRA) patients, our understanding is still incomplete. To address this, we performed single-cell RNA sequencing of CD45+ cells from peripheral blood samples of drug-naïve ACPA+ and ACPA- eRA patients and compared distribution and functional characteristics of cell subsets based on ACPA presence.
Project description:The presence of autoantibodies to citrullinated protein antigens (ACPAs) in the absence of clinically-apparent inflammatory arthritis (IA) identifies individuals “at-risk” for developing future clinical rheumatoid arthritis (RA). However, it is unclear why some ACPA+ individuals convert to clinical RA while others do not. We explored the possibility in the Targeting Immune Responses for Prevention of Rheumatoid Arthritis (TIP-RA) study that epigenetic remodeling is part of the trajectory from an at-risk state to clinical disease and identifies novel biomarkers associated with conversion to clinical RA.
Project description:Citrullinated and unmodified peptides (>95% purity, ProImmune AB) were immobilized onto a chemically modified glass slide, sera from RA patients and healthy controls were applied into the reactions sites and fluorescence intensity after incubation with anti-human IgG antibody was acquired in a laser scanner. Final results for each citrullinated peptide were calculated by subtracting the intensity values of corresponding arginine containing control peptide from citrullinated peptide for all RA patients and controls.
Project description:Antigen-specific regulation of autoimmune disease is a major clinical research goal. In seropositive rheumatoid arthritis (RA), T cells help to autoreactive B cells matures the citrullinated antigen-specific immune response, generating RA-specific V-domain glycosylated anti-citrullinated (Cit) protein antibodies (VDG ACPA) before arthritis onset. Repeated low or escalating antigen doses administered under “sub-immunogenic” conditions generally favors tolerance. The aims of this study were to explore the safety, pharmacokinetics, immunological and clinical effects of s.c. DEN-181, comprising liposomes encapsulating self-peptide collagen II259-273 (CII) and NF-KB inhibitor 1,25-dihydroxycholecalciferol (calcitriol)
Project description:Transcriptional profiling of human synovial tissue from thirteen individuals with arthralgia who were IgM rheumatoid factor (RF) and/or anti-citrullinated protein antibody (ACPA) positive and without any evidence of arthritis. Survival analysis was used to identify transcripts associated with arthritis after follow up. This study was performed to investigate the molecular changes in synovium preceding arthritis development in at risk individuals.
Project description:Anti-citrullinated protein antibodies (ACPAs) are one of the hallmarks in rheumatoid arthritis (RA), but the in vivo function remained unclear. To investigate the effects of ACPAs, we expressed monoclonal ACPAs derived from RA patients, and analyzed the functions in mouse models, as well as the reactivity to tissue and peptides/proteins. All ACPAs showed no arthritogenicity and could not induce pain-like behavior in mice whereas one of them (E4) profoundly protected against antibody-induced arthritis. E4 showed a tissue binding pattern restricted to skin epithelial cells, to macrophages and dendritic cells in lymphoid tissue and to cartilage from mouse and human arthritic joints. Proteomic analysis showed that E4 had a distinct binding pattern to macrophage and RA synovial fluid proteins (e.g. alpha-enolase). The protective effect was epitope specific but also dependent on Fc-FCGR2B interaction on macrophages following the immune complex formation, resulting an increased IL-10 production and osteoclastogenesis reduction. The findings suggest that certain ACPAs could be protective in arthritis with therapeutic potentials.
Project description:Anti-citrullinated protein antibodies (ACPAs) are one of the hallmarks in rheumatoid arthritis (RA), but the in vivo function remained unclear. To investigate the effects of ACPAs, we expressed monoclonal ACPAs derived from RA patients, and analyzed the functions in mouse models, as well as the reactivity to tissue and peptides/proteins. All ACPAs showed no arthritogenicity and could not induce pain-like behavior in mice whereas one of them (E4) profoundly protected against antibody-induced arthritis. E4 showed a tissue binding pattern restricted to skin epithelial cells, to macrophages and dendritic cells in lymphoid tissue and to cartilage from mouse and human arthritic joints. Proteomic analysis showed that E4 had a distinct binding pattern to macrophage and RA synovial fluid proteins (e.g. alpha-enolase). The protective effect was epitope specific but also dependent on Fc-FCGR2B interaction on macrophages following the immune complex formation, resulting an increased IL-10 production and osteoclastogenesis reduction. The findings suggest that certain ACPAs could be protective in arthritis with therapeutic potentials.
Project description:Protein citrullination modification plays a pivotal role in the pathogenesis of rheumatoid arthritis (RA), and anti-citrullinated protein antibodies (ACPAs) are extensively employed for clinical diagnosis of RA. However, there remains limited understanding regarding specific citrullinated proteins and their implications in the progression of RA. In this study, we screened and verified insulin-like growth factor-2 mRNA binding protein 1 (IGF2BP1) as a novel citrullinated protein and R167 was the primary citrullination site. Functional verification showed that citrullination at the R167 site of IGF2BP1 promoted the proliferation, migration and invasion of RA fibroblast-like synoviocytes (RA-FLSs). To further explore the specific downstream target of citrullinated IGF2BP1, RNA sequencing was conducted in this study.
Project description:Association of Epigenetic Trajectory With Development of Clinical Rheumatoid Arthritis in Individuals With Anti–Citrullinated Protein Antibody Positivity: Targeting Immune Responses for Prevention of Rheumatoid Arthritis (TIP-RA)